WO2017021463A1

WO2017021463A1 - Casting device for applying a foaming reaction mixture

Info

Publication number: WO2017021463A1
Application number: PCT/EP2016/068574
Authority: WO
Inventors: Dirk Brüning; Achim Symannek; Klaus Franken; Stephan Schleiermacher; Thomas Herweg
Original assignee: Covestro Deutschland Ag
Priority date: 2015-08-04
Filing date: 2016-08-03
Publication date: 2017-02-09
Also published as: EP3331683A1; US20180222093A1; CN107848167A; CA2994602A1

Abstract

The invention relates to a casting device (100) for applying a foaming reaction mixture (10), at least comprising polyol and isocyanate, to at least a partial width of a cover layer (11), in particular for producing a compound element (1), wherein the casting device (100) comprises: a supply connection (12) for feeding in the reaction mixture (10); at least one exit slit (13) extending in a transverse direction (Q) for the exiting of the reaction mixture (10); two slit plates (14) arranged opposite one another, wherein a slit space (15) extends between the slit plates (14) in a vertical direction (H) above the exit slit (13). According to the invention, a supply channel (16) connected to the supply connection (12) is formed between the slit plates (14), which closes off the slit space (15) above the exit slit (13) in the vertical direction (H), wherein the supply channel (16) has a channel cross-section (17), the main dimension of which is larger that the width (B) of the slit space (15), such that the reaction mixture can be introduced into the slit space (15) in such a way that it is distributed over the length of the supply channel (16).

Description

Casting device for applying an intumescent reaction mixture

The invention relates to a casting device for applying an intumescent reaction mixture comprising at least a partial width of a cover layer, in particular for producing a composite element, wherein the casting device has an inlet connection for feeding the reaction mixture and an exit gap extending in a transverse direction to the exit of the Reaction mixture forms, and wherein the casting device has two oppositely arranged split plates, wherein extending in a height direction above the outlet gap, a gap space between the gap plates.

STATE OF THE ART

EP 2 216 156 A1 discloses a casting apparatus for applying an intumescent reaction mixture comprising polyol and isocyanate for the production of composite elements. Composite elements have at least one and mostly two cover layers guided parallel to one another, and the reaction mixture is applied to one of the cover layers, in particular on the inside of a lower cover layer guided on the bottom side. After the reaction mixture has been applied, it foams until the foam front reaches the inside of the opposite cover layer. The cover layers are guided in a parallel belt system until the reaction mixture has hardened to form a substantially dimensionally stable body which forms the polyurethane foam core between the two cover layers. This continuous production of composite elements is characterized by a high output, and the endlessly produced composite element can be singled after passage through the parallel belt system in corresponding sandwich elements.

The quality of the sandwich elements depends essentially on how uniform and volume-filling the polyurethane foam core is formed between the two cover layers. Also, the adhesion of the cover layers to the interface of the polyurethane foam core plays an essential role in assessing the quality of the composite element. If several strands of reaction mixture in the width direction of the cover layer side by side applied to the inside of the cover layer, the foaming of the reaction mixture leads to a plurality of foam fronts which come to one another and between which consequently form interfaces. The result is an uneven foaming of the reaction mixture with several foam fronts and when cured, the polyurethane foam core has an inhomogeneous texture. In this case, there are formed overflows with bubbles and voids, the cell orientation of the foam is usually not uniform. As a result, the quality of the foam structure decreases, and too low adhesion to the inside of the cover layers can be the result and it can lead to a reduced quality of the composite elements, in particular with regard to mechanical and / or thermal properties, surface quality and / or compressive strength.

From GB 1 282 876 A, a casting apparatus with a slot die is known, which allows a oriented in the width direction of the outer layer line application of a reaction mixture comprising polyol and isocyanate. In the design of such slot dies, it is important to provide a uniform as possible application of the reaction mixture on the cover layer in order to achieve an equally uniform foaming. It is not sufficient to produce the same volume flow at each position of the exit slit in its length along the transverse direction, since the passage time of the reaction mixture through the casting apparatus is just as crucial. Portions of the reaction mixture which deposit a longer flow path through the casting apparatus foam after pouring onto the topcoat earlier than portions of the reaction mixture that have taken a faster, more direct path through the casting apparatus. Decisive is the time of passage of the reaction mixture through the casting apparatus, which should be as equal as possible to each stream of the reaction mixture.

The casting apparatus disclosed in GB 1 282 876 A has a plurality of inlet connections which open in a punctiform manner into a gap formed between the split plates. In operation, the reaction mixture is fed into the gap space through the feed ports, and the gap space is in the shape of a triangle, and the elongate lower bottom edge of the triangle forms the exit gap. Thus, there is already no possibility that each volume unit of the reaction mixture passes through the casting apparatus with the same period of time, as in the middle of the base edge directly below the inlet connection a shorter flow time of the reaction mixture is achieved than in the edge regions. A further disadvantage is that due to the triangular shape no uniform outflow velocity of the reaction mixture from the outlet gap can be established, since a higher pressure drop prevails in the edge area of the triangular structure of the gap spaces as a result of the longer flow path than in the middle. Due to the constant pressure difference for each flow path from the inlet into the triangular gap to the outlet is idealized set a Gaussian distribution of the flow velocity along the lower base edge of each of the triangular-shaped pouring dies, resulting in a nonuniform discharge amount and uneven foaming of the reaction mixture. Composite elements of the type of interest here are also referred to as sandwich elements or insulation boards and are usually used as components for sound insulation, for hall construction or for facade construction. The cover layers can form metal tracks or plastic tracks, depending on the intended use of the composite elements. DISCLOSURE OF THE INVENTION

The object of the invention is the development of a casting apparatus for applying a foaming reaction mixture, with which a uniform foaming of the reaction mixture over the outer layer width is to be achieved. In particular, the casting device should be formed such that each volume element of the reaction mixture over the length of the outlet gap of the casting device passes through this with an equal period of time.

This object is achieved on the basis of a casting device for applying a foaming reaction mixture according to the preamble of claim 1 and with a system for applying a foaming reaction mixture with a plurality of pouring devices according to claim 10 with the respective characterizing features. Advantageous developments of the invention are specified in the dependent claims.

The invention includes the technical teaching that an inlet channel connected to the Zulauianschluss between the gap plates is formed, which closes the gap above the outlet gap in the height direction, wherein the inlet channel has a channel cross-section whose main dimension is greater than the width of the gap space, so that the Reaction mixture over the length of the inlet channel distributed in the gap space can be introduced.

The core of the invention is a special embodiment of the casting apparatus with a guide of the reaction mixture between the Zulauianschluss and the exit slit, which is developed so that each volume unit of the reaction mixture between the Zulauianschluss and the exit slit can pass through the casting device with the same cycle time. In other words, each current thread of the reaction mixture between the Zulauianschluss and the exit slit on the same residence time. This solution is achieved with an inlet channel, the adjoins the inside of the casting device to the inlet port and wherein the inlet channel is formed between the gap plates.

The design "between" the split plates describes an embodiment of the inlet channel which is formed either in a first gap plate, in an opposing second gap plate or in both gap plates by a corresponding geometry The cross section of the inlet channel does not have to be round, but can also be In particular, the inlet channel can also be formed by forming a corresponding recess, for example with a semicircular channel cross-section, in only one of the two split plates The opposite gap plate can have a plane surface and the inlet channel limit laterally or the opposite gap plate has the same or a modified recessed geometry in a mirrored manner to form the channel cross-section symmetrically over the gap space s feed channel "between" the gap plates in the sense of the present word use any shape of recesses and other geometries in the surface of the gap plate.

Of course, the gap may be incorporated in both split plates or only one side in one of the split plates. In particular, it is also possible to introduce the inlet channel with the inlet connection and the gap space only in a gap plate, since then in a particularly advantageous manner, the opposite gap plate can be performed completely flat.

The main dimension of the channel cross-section is wider than the width of the gap, so that the reaction mixture can reach the end of the inlet channel, wherein the channel cross-section of the inlet channel is formed so that a defined pressure drop of the flow mixture is generated with increasing distance from the inlet connection. The reaction mixture leaves the inlet channel evenly distributed over its entire length and passes in the manner of a flow curtain in the gap, which adjoins below the inlet channel. As a result, a line effluent of the reaction mixture is generated from the feed channel, so that the reaction mixture can be introduced into the gap space distributed over substantially the entire length of the feed channel. The length of the inlet channel extends in the transverse direction in the length, which also corresponds to the length of the outlet gap. In particular, the ends of the outlet gap close with the ends of the inlet channel. According to an advantageous development of the casting device according to the invention, the channel cross section is formed smaller with increasing distance from the Zulauianschluss. The channel cross section is advantageously the largest in the connection point to the Zulauianschluss and with increasing distance from the Zulauianschluss the channel cross section increasingly decreases. The inlet channel may extend in the transverse direction on both sides equally away from the Zulauianschluss, and the inlet channel has following the Zulauianschluss the largest cross section aui. The respective outer ends of the inlet channel can have such a small cross-section that it closes with the width of the gap space. This avoids that at the ends of the inlet channel an increased amount of reaction mixture can escape from the outlet gap.

The width of the gap space may be the same with the width of the exit slit or the width of the exit slit is at least slightly smaller than the width of the gap space, in particular to still get a residual pressure difference in the reaction mixture before and after passing through the exit slit, thereby still a further homogenization of the exit of the reaction mixture results.

In a further embodiment, the width of the outlet gap can be made larger starting from the width of the gap space, starting from the outlet opening, in order to reduce the exit velocity or to counteract an increase in volume at the start of the foaming.

It is also advantageous if the gap space has a width that is constant over the substantially entire areal extent of the gap space between the gap plates, but small local deviations of the width from the otherwise the same width everywhere may occur, for example in places where where screws run through the gap. In addition, it is advantageous if the inlet channel has a curvature, so that the height of the gap space becomes smaller with increasing distance from the Zulauianschluss over the outlet gap. With increasing distance from the Zulauianschluss thus decreases the height of the gap space between the exit slit and the inlet channel, so that the flow resistance and the flow time between the inlet channel and the outlet slit decrease. At the same time, however, the flow resistance increases over a longer distance through the inlet channel, so that the total pressure loss remains constant. The fact that the flow velocity in the inlet channel is higher than in the gap, is achieved in total that the Reaction mixture between the inlet port and the outlet gap over the entire length of each flow path experiences the same cycle time.

The changing channel cross-section of the inlet channel and the curvature for adjusting the height dimension of the gap above the outlet gap are coordinated so that the same over the entire length of the outlet gap same cycle time of the reaction mixture is generated. Thus, it is also conceivable to form the curvature of the inlet channel with increasing distance from the inlet connection becoming larger. The inlet channel may for example have an approximately parabolic curvature, the curvature increasing with increasing distance from the inlet connection. As a result, the inlet channel receives approximately the shape of a hanger, so that in particular the marginal boundary of the planar gap space deviates from a triangular shape. Rather, the gap between the outlet gap and the inlet channel extends with a total of constant width, and by the same width across the entire areal extent of the gap width results in addition to a homogenization of the flow velocity. As a special feature can be achieved that the reaction mixture over the entire length of the exit slit in the transverse direction has the same exit velocity.

The coordination of the size ratios and geometries of the components of the casting device involved in the guidance of the reaction mixture takes place, for example, computer-aided, preferably with a computer-fluid dynamic calculation (CFD). The length of the inlet connection and / or the length of the inlet channel and / or the height of the gap space in the height direction above the outlet slit are determined so that the volume elements of the reaction mixture over the entire length of the exit slit can experience a mutually same cycle time that each volume element on the length of the exit slit has a mutually equal velocity value and that the passage time of the reaction mixture through the casting device is smaller than the reaction time. By this is meant that the passage time of the reaction mixture from the mixing head, which is upstream of the inlet connection, and the outlet gap, is chosen so small that in the reaction mixture is not already used before exiting the outlet gap foaming.

The invention further relates to a system for applying a foaming reaction mixture at least comprising polyol and isocyanate on at least a partial width of a cover layer, in particular for producing a composite element, comprising a plurality of casting devices according to one of claims 1 to 9, wherein the exit column of Casting devices extend in a common transverse direction or arcuately over the cover layer.

Core of the system according to the invention is a juxtaposition of several casting devices according to the invention, so that the total length of the exit slit is adapted in the common transverse direction to the cover layer width. As a result, the possibility is created to make the casting device smaller and thus reduce the throughput time, and the individual, several gap spaces, which are bounded on the upper side by respective inlet channels, form individual casting devices, but the length of the entire outlet gap does not have to correspond to the cover layer width , Each of the individual casting devices can have a separate inlet connection, which is fed by separate mixing heads in each case, with the advantage that it is also possible to feed the multiple inlet connections with one mixing head. For supplying the reaction mixture to the inlet connections, a hose system or a pipe distributor system can be provided.

According to an advantageous development of the system, the split plates of the plurality of casting devices may be integrally formed with each other on one or each side of the gap. In a one-piece design, the various feed channels can be fed via a central inlet connection and a downstream, for example star-shaped, distribution system. The split plates can be shaped in such a way that a plurality of inlet channels and gap spaces adjoining the inlet channels are formed. In particular, it is conceivable to associate each inlet channel with its own inlet connection. It is also advantageously possible for the ends of the inlet channels of the plurality of casting devices which are remote from the inlet connections to adjoin one another. If the transit time and the exit velocity of the reaction mixture from the exit slit of the individual casting devices are the same across the respective gap length in the transverse direction, it is to be expected that the transit time and the exit velocity of the reaction mixture will be the same along the entire exit slit. This ensures that overall a constant, uniform application of the reaction mixture is achieved over the entire cover layer width. The total length of the exit slit corresponds to almost the outer layer width, wherein it may be provided to select the application width of the reaction mixture slightly smaller than the outer layer width. For example, the cover layer may have a width of 120 cm, and the total length of the exit slit is for example, 115 cm and extends in the width direction over the cover layer. The smaller application width of the reaction mixture in relation to the width of the cover layer is preferably selected in order to avoid unintentional discharge outside the cover layer. Since the reaction mixture also foams and expands in the cover layer width, the edge region of the cover layer is thus also reached and covered.

In the system, the at least one casting device can be tiltably received about an axis, for example, parallel to the cover layer and perpendicular to the transport direction of the cover layer, so that the device does not have to apply the reaction mixture exactly perpendicular to the cover layer but, for example, stinging or dragging. By means of the tilted position, the angle between the discharge film and the cover layer can be adjusted in such a way that optimum flow conditions of the reaction mixture in the impact area result.

In the system, the at least one casting device can also be rotatably arranged about an axis perpendicular to the lower cover layer. Depending on the choice of the angular position of the casting device and thus the angle between the exit slit and the transport direction of the cover layer, the application width of the reaction mixture is adapted to the cover layer width and / or the leadership of the rising foam, which is formed from the reaction mixture, when reaching the upper cover layer favorably influenced.

When juxtaposing several casting devices, these are accommodated, for example, on an adjustable support, wherein, as described above, the plurality of casting devices can also be formed in a structural unit, for example with common split plates.

When using a plurality of casting devices, these are preferably arranged so that the outlet gaps of the individual casting devices form a common, continuous and straight or curved outlet gap. In an extended embodiment, these can also be rotated relative to one another in such a way that the individual exit gaps in each case enclose an angle relative to one another and together form a polygon or an arc. This results in an even better adaptability to the cover layer width and / or guidance of the rising foam when reaching the upper cover layer.

With further advantage, it is provided to provide the reaction mixture with a gas loading and in particular with an air charge. By an air loading is clogging of the Gap space avoided in particular in the reaction mixture with weaker flow through areas of the gap. For this purpose, the system has a gas loading device, with which the reaction mixture is laden with a gas. The gas loading device is designed so that the gas loading with air, with nitrogen, with carbon dioxide or with noble gas, in particular argon or helium, can be made. In particular with dried air or with nitrogen, it is advantageously achieved that the thin gap between the split plates does not become clogged with a pre-foaming reaction mixture.

PREFERRED EMBODIMENT

Further, measures improving the invention will be described in more detail below together with the description of a preferred embodiment of the invention with reference to FIGS. It shows:

Figure 1 is an overall view of the system with a casting apparatus and the

Feeding of cover layers and a double belt transport system,

Figure 2 is a perspective view of a gap plate 14 of the one

Side that limits the gap space,

Figure 3 is a cross-sectional view of the casting apparatus with two

successive split plates forming the gap space between the split plates,

Figure 3 a a modified embodiment of the exit slit with

this trained slit lips

Figure 4 is a perspective view of a continuous gap plate, the

forms several individual casting devices and

Figure 5 is a perspective view of a part of a casting apparatus with

the split plates arranged adjusting means. FIG. 1 shows a schematic view of a plant for operating a process which is used to produce composite elements 1. The system has a double band Transport system 21, enter the two outer layers 11. A lower cover layer 11 is unrolled from a cover layer roll 20 and an upper cover layer 11 is also unrolled from another cover layer roll 20. The two cover layers 11 are retracted with an intermediate space in the transport system 21, and on the inner surface of the lower cover layer 11, a reaction mixture 10 is applied with a casting apparatus 100. The casting apparatus 100 connects via an inlet connection 12 to a mixing head 19, and in the mixing head 19, shown with two arrows, at least the components polyol and isocyanate entered with a corresponding mixing ratio, with a possible air loading of the reaction mixture 10 may be provided , which is not shown for simplicity.

The casting apparatus 100 is positioned at a distance from the double-belt conveyor 21 in such a way that the reaction mixture foams over a foaming path so that the underside of the upper cover layer 11 is achieved by foaming and can pass through the double-belt conveyor 21 during passage of the composite element 1 thus formed the polyurethane Verschaunernern between the two outer layers 11 cure. After passing through the double-belt conveyor 21, the continuous material of the composite element 1 can be separated to form individual sandwich panels in a manner not shown in detail. Figure 2 shows an example of a gap plate 14, wherein the perspective view is selected such that the gap space 15 is visible, the counter-gap plate is removed to represent the flat-shaped gap space 15. The gap plate 14 shown has recesses 23 for receiving fasteners, so that two gap plates 14 can be brought to each other to form the casting apparatus 100 and thereby complete the gap 15.

By way of example, an inlet connection 12 for supplying reaction mixture 10 is shown, and inlet connection 12 is fluidically connected to an inlet channel 16, which is introduced into gap plate 14. The inlet channel 16 branches off after an intermediate channel 24 for connection to the inlet port 12 on both sides of a transverse direction Q, so that the inlet channel 16 has two branches which extend laterally away from the inlet port 12.

Thus, by way of example only, a symmetrical design of the casting device is shown, which alternatively can also be asymmetrical only on one side of the inlet connection 12, so that only one branch of the inlet channel 16 adjoins the inlet connection 12. The lower edge of the gap plate 14, together with the not shown further gap plate 14 an exit slit 13. The exit slit 13 extends in its length over the transverse direction Q between the two ends of the inlet channel 16, and the inlet channel 16 is curved so that this with increasing distance from the inlet port 12 of the edge of the exit slit 13 approaches and finally terminates with this end. The larger the distance from the inlet port 12, the smaller the height of the gap 15 in the height direction H. The inlet channel 16 itself is introduced as a groove-like depression in the gap plate 14 and has a channel cross-section 17, which increases with increasing distance from the inlet port 12th rejuvenated.

The changing channel cross-section 17, the curvature in the inlet channel 16 and thus the changing height in height direction H of the gap space 15 are coordinated so that the reaction mixture 10 over the entire length of the exit slit 13, the same cycle time through the casting device 100 learns and the exit velocity of the reaction mixture 10 from the exit slit 13 is also equal over the length of the entire exit slit 13.

3 shows a cross-sectional view through the casting device 100 with cross-cut split plates 14. A gap space 15 can be seen, which extends between the two split plates 14 and extends in the height direction H from the inlet channel 16 to the lower-side outlet gap 13. The gap 15 has over its areal extent a constant width B, and the areal extent results between the inlet channel 16 and the exit slit 13 in the height direction H and the transverse direction Q, on which the height direction H is vertical.

FIG. 3 a shows a modified embodiment of the outlet gap 13 with gap lips 26 formed thereon, wherein the gap lips 26 protrude above the plate end of the gap plates 14 and form thin lip-like projections. This prevents the formation of reaction mixture in the outer region of the outlet slit 13, which could interfere with the exit of the reaction mixture on the outer surface of the slit plates 14 with larger amounts accumulated.

Figure 4 shows two juxtaposed individual pouring devices 100, which are arranged in the transverse direction Q side by side so that a single continuous Exit gap 13 results. If the respective feed connections 12 are supplied with reaction mixture 10, then the reaction mixture 10 with the advantages described above passes through the respective feed channels 16 of the pouring devices 100 and exits via the common exit gap 13 with twice the exit length. Overall, this results in an enlarged line width for application of the reaction mixture 10 at smaller formed individual gap spaces 15, and for a width of the cover layer 11, for example, with a width of 120 cm , not a single gap plate 14 must be provided with a continuous gap space 15, but it can be a plurality of individual gap spaces 15 are formed under associated feed channels 16.

Finally, FIG. 5 also shows a perspective view of a part of the casting apparatus 100 with two gap plates 14 placed on one another and a gap space 15 between the split plates 14. In order to adjust the outlet gap 13 in width B, the length of the outlet gap 13 is in FIG Transverse Q distributed distributed adjusting means 18, which can adjust an associated portion of the exit slit 13 in width B via actuators 22. By appropriate adjustment of the adjusting means 18 via the actuators 22, for example, with an associated tool, the exit slit 13 in its width B can be adjusted so that the uniformity of the order of the reaction mixture 10 can be further improved. Associated dial gauges 25 thereby allow a control of the width B, which is associated with the respective adjustment means 18.

The invention is not limited in its execution to the above-mentioned preferred embodiments. Rather, a number of variants is conceivable, which makes use of the illustrated solution even with fundamentally different types of use. Any features and / or advantages resulting from the claims, the description or the drawings, including constructive details or spatial arrangements, can be essential to the invention, both individually and in the most diverse combinations. LIST OF REFERENCE NUMBERS

100 pouring device 1 composite element

10 reaction mixture

11 cover layer

12 inlet connection

13 exit slit

14 split plate

15 gap space

16 intake channel

17 channel cross section

18 adjustment means

19 mixing head

20 cover layer roll

21 double belt transport system

22 actuators

23 recess

24 intermediate channel

25 Dial gauge

26 slit lip

Q transverse direction

H height direction

B width

Claims

Casting device (100) for applying a foaming reaction mixture (10) comprising at least polyol and isocyanate on at least a partial width of a cover layer (11), in particular for producing a composite element (1), the casting device (100) having:

an inlet connection (12) for feeding in the reaction mixture (10), at least one outlet gap (13) extending in a transverse direction (Q) for exiting the reaction mixture (10),

two splitting plates (14) arranged opposite one another, a gap space (15) extending between the splitting plates (14) in a height direction (H) above the outlet gap (13),

characterized in that

an inlet channel (16) connected to the inlet connection (12) is formed between the gap plates (14), which closes the gap space (15) above the outlet gap (13) in the height direction (H), where

the inlet channel (16) has a channel cross section (17), the main dimension of which is larger than the width (B) of the gap space (15), so that

the reaction mixture can be introduced into the gap space (15) distributed over the length of the inlet channel (16).

Casting device (100) according to claim 1, characterized in that the channel cross section (17) becomes smaller as the distance from the inlet connection (12) increases.

Casting device (100) according to claim 1 or 2, characterized in that the gap space (15) has a width (B) which is designed to be constant over the essentially entire surface extent of the gap space (15) between the gap plates (14).

Pouring device (100) according to one of claims 1 to 3, characterized in that the inlet channel (16) has a curvature, so that the gap space (15) has a decreasing height above the outlet gap (13) as the distance from the inlet connection (12) increases .

5. Pouring device (100) according to claim 4, characterized in that the curvature of the inlet channel (16) becomes larger as the distance from the inlet connection (12) increases.

Casting device (100) according to one of the preceding claims, characterized in that the changing channel cross section (17) of the inlet channel (16) and/or the curvature of the inlet channel (16) and/or the formation of the gap space (15) are determined in such a way that that the exit velocity of each volume element of the reaction mixture (10) has the same velocity value over the length of the exit gap (13).

Casting device (100) according to one of the preceding claims, characterized in that the changing channel cross section (17) of the inlet channel (16) and/or the curvature of the inlet channel (16) and/or the formation of the gap space (15) are determined in such a way that that each volume element of the reaction mixture (10), based on the length of the outlet gap (13), has an identical throughput time from the inlet connection (12) to the exit from the outlet gap (13).

Pouring device (100) according to one of the preceding claims, characterized in that the length of the inlet connection (12) and/or the length of the inlet channel (16) and/or the height of the gap space (15) in the height direction (H) above the outlet gap (13) are determined so that the throughput time of the reaction mixture (10) is less than the reaction time.

Casting device (100) according to one of the preceding claims, characterized in that adjusting means (18) are provided with which the width of the outlet gap (13) can be adjusted, with a plurality of adjusting means (18) being provided distributed over the length of the outlet gap (13). .

System for applying a foaming reaction mixture (10) comprising at least polyol and isocyanate on at least part of the width of a cover layer (11), in particular for producing a composite element (1), comprising a plurality of casting devices (100) according to one of claims 1 to 9, wherein the outlet gap (13) of the casting devices (100) extend in a common transverse direction (Q) or over an arc above the cover layer (11). Plant according to claim 10, characterized in that the gap plates (14) of the plurality of casting devices (100) on each side of the gap space (15) are formed in one piece with one another.

Plant according to claim 10 or 11, characterized in that the ends of the inlet channels (16) of the plurality of casting devices (100) remote from the inlet connections (12) adjoin one another.

Plant according to one of claims 10 to 12, characterized in that the plant has a gas loading device with which the reaction mixture (10) can be loaded with a gas.

Plant according to claim 10, characterized in that the gas loading can be operated with air, with nitrogen, with carbon dioxide or with noble gas, in particular argon or helium.